Paper making



Aug. 11, 1925.

F. BA RNES' PAPER MAKING Filed Dec. 12, 1923 Fred Barnes, 2

r W a n m ww E./// v w M Patented Aug. M, 19.25..

FRED BARNES, Q15 SHAVIINIGAN FALL, QUEBEC, CANADA.

PAPER MAKING.

Application filed December 12, 1923. Serial No. 680,122.

To all whom it m my concern:

Be it known that I, FRED BARNES, of Shawinigan Fall, Province of Quebec, Dominion of Canada, a subject of the King of Great Britain, have invented certain new and useful Improvements in Paper liiaking; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates particularly to the manufacture of newsprint paper although it is applicable to the production of pulp for all classes of paper containing wood pulp and has for its object to enhance the quality of ground wood pulp. To this end my invention may be said broadly to consist in providing special treatment for the pulp after it has been ground, screened and thickened or deckered. Heretofore has been the practice to dilute the thickened deckered stock from approximately 5% consistency to about 3.5% which is maintained. lVith this consistency the stock after mixing with sulphite is taken to the paper machine chest and thence to the paper machines where it is diluted and made into paper. The special treatment provided by my invention consists in taking the deckered stock to a digesting system in which the ground wood pulp is uniformly hydrated and where it may be, at the same time thoroughly mixed with the sulphite if desired.

More specifically stated my improved process consists in deflecting the Woodstock from the thickener to a system consisting preferably of a series of three tanks or di gesters of suitable capacity, according to the capacity of the mill. These tanks or digesters are charged with the Woodstock and operated successively to impart enhanced quality and value to the stock. This is effected by subjecting the stockin its inferior state to a stock heater where its temperature is raised sufiiciently to bring its capacity for water absorption to the required degree. The heated stock is then charged into the first tank of the series through which and the heater it is made to slowly circulate for about four hours. If desired rotary stirrers may be located in the tanks to supplement the circulatory action.

The effect is that the pulp mixture is increased substantially in strength by uniform hydration thus producing a stronger paper with a better finish than can be obtained by the process superceded; furthermore the production is increased by permitting the paper machines to be speeded up. Another advantageous effect is that the breaks in the paper may be greatly reduced. The proportion of sulphite pulp may also be reduced. These advantageous effects are due to the deflection of the deckered stock to my hydrating and mixing system.

For full comprehension, however, of my invention reference must be had to the accompanying drawing which illustrates diagrammatically the hydrating and mixing system forming the principal feature of the paper making system for carrying on my improved process.

The grinders, screen and finishers or deckers are not illustrated and will not be described by me as they are very well known to the paper making industry. The deckered stock is taken by a pipe 3 extended horizontally over a series of three circular tanks 4, 5 and 6 respectively. Branch pipes 7 8 and 9 respectively lead downwardly to within close proximity of the series of three heating drums 10, 11 and 12 respectively heated by exhaust steam from a neighboring power or heating plant or by any other suitable means. A circulating pipe 20 has three branches 21, 22 and 28 respectively which communicate with the bottom of the tank, the opposite end of pipe 20 being taken up and along over the tops of the tanks as at 25. It is provided with three downwardly extending branches 26, 27 and 28 also extending to within close proximity of the heating drums 10, 11 and 12. The branches 7, 8 and 9 are controlled by valves 13, 14 and 15, and valves 16, 17 and 18 control the branches 21, 22 and 23; while the branches 26, 27 and 28 are controlled by valves 29, 30 and 31. A stock discharge pipe leads to a cooling and diluting tank 36 from which the stock is fed to the paper machines. This pipe 35 is connected to the respective tanks by a series of three branches 37, 38 and 39 controlled respectively by valves 40, 41 and 12. The pipe 2025 with the branches of the latter and the tanks forms a circulating system through which the stock is caused to travel by a pump indicated at 45. A heating coil indicated at 4:6 or other suitable means is provided for use 1f required to supplement or take the place of the heating drums, The stock is detached cated at 7 5 with suitable clutch mechanism 76 whereby the operation of the stirrers in any particular tank may be controlled. v

The operation of the paper making proc- .ess including my improved hydrating and mixing system isas follows:

Valves 13, 16 and 29 are open andthe remaining valves closed, the heating drums and heating coils are heated to yield to the stock a temperature of between 110 F. and 155 F. the. temperature employed depending upon the type of pulp being ground. The cooler is equipped with cooling mechanism adapted to be regulated to reduce the temperature of the stock to that of the paper machines.

To start the system the grinders are started eight hours before the paper machines, say at midnight. The first tank is filled in four hours time. As soon as it is full the pump is started and the stock caused to circulate and the mixer is started. The circulation through this tank is continued for four hours and the temperature of the stock is raised to, preferably 135 F. as an average, but varies with the type of pulp. This tempreature is established shortly after the tank is filled and it is maintained for four hours. As it takes approximately four hours to fill the tank and four hours is consumed in the circulating and mixing opera tion the contents of the first tank is ready for the paper machines at say eightoclock 1n the morning. The effect of this circulating and stirring is that the stock is uniformly hydrated and thoroughly mixed thus completely digesting it. hen this operation of the first tank is completed valve 40 is opened and the stock is fed to the cooler and its temperature is reduced to that of the paper machines. As soon as the first tank has been filled the valve 13 is closed and valve 14 opened and the operation just described in connection with the first tank is repeated in connection with the second. tank 5; and the third tank 6 is operated in a similar manner. 'By the time the contents of the first tank has been fed to the paper machines the third tank has been filled and the valve 15, which will have been opened for the operation of the tank 6 isclosed and valves 13 may be reopened and the filling of tank 4 be re-com1nenced. As soon as the contents of tan'kfi have been circulated and tion and the supply of stock to the paper machines after the system is fairly started, is continuous.

The steps of the process in so far as grinding and mixing and preliminary mixing are concerned is as at present commonly practised :in the paper making industry as is also the operation in passing through the paper making machines per se, and I make no claim to these steps of the process except as they occur in my complete paper, making process in which these steps are included.

What I claim is as follows:

1. In the manufacture of paper, a process in which. the deckered ground wood stock is subjected to a digesting action.

2. In the manufacture of paper, the process of grinding wood. mixing the deckered ground wood with sulphite pulp, subjecting the stock to a digesting action, cooling and diluting the stock and finally feeding the same to a paper making machine.

3. In the manufacture of paper, the process of grinding wood, mixing the-deckercd ground wood with sulphite pulp, subjecting the stock to a digesting action with heat, cooling and diluting the stock and finally feeding the same to a paper making machine.

4-. "in the manufacture of paper the procsee of grinding wood. mixing deckered {Ti-mind wood with sulphite pulp, feeding the stock to a dige ting tank and simultaneously heating the same, circulating the stock through the digesting tank, cooling and diluting the stock andfin ally feeding the same to a paper making machine.

5. Tu the manufacture of paper the process of grinding wood, mixing deckered ground wood with sulpliite pulp. feedingthe stock to a digesting tank and simultaneously heating the same. circulating the stock through the digesting tank, stirring the heated stock within the tank during the c rculating step. cooling and diluting the stock and finally feeding the same toa paper making machine.

6. In the manufacture of paper, the process of grinding wood, mixing the deckered ground'wood with sulphite pulp, feeding the stock to one of a series of digesting tanks and simultaneously heating the same, circulating the stock through the said digesting tank, cooling and diluting the stock and finally feeding the same to a paper making machine.

7. In the manufacture of paper, the process of grinding wood, mixing the deckered ground wood with sulphite pulp feed ing the stock to one of a series of digesting tanks and simultaneously heating the same, circulating the stock through the said digest ing tank, cooling and diluting the stock and finally feeding the same to a paper making machine and stirring the circulating stock lU i Il-U

while passing through the digesting tanks.

8. In a paper making plant, a stock digesting system consisting of a digesting ,tank, stock heating means, means for circulating the stock through the heating means and tank, and means for discharging the digest ing stock from the tank.

9. In a paper making plant, a stock digesting system consisting of a digesting tank, stock heating means, means for circulating the stock through the heating means and tank, means for discharging the digesting stock from the tank, a stock stirrer Within the tank and means for opera-ting the same.

10. In a paper making plant a stock adjusting system consisting of a series of digesting tanks, stock heating means adjacent each tank of the series, means for feeding stock consisting of a main feed pipe with valve controlled branches directing stock flowing through each heating means to the several tanks of the series, means for circulating the stock through the heating means and tank of the series consisting of a main circulating pipe with branches communicating with the bottoms of the several tanks of the series and having a series of valve controlling branches directing the flow of the stock through the heating means of the several tanks of the series, and such branches having controlling valves, a pump connected to and forcing the stock through the main circulating pipe, and means for discharging the digesting stock from the tank, consisting of a main discharge pipe with branches communicating with the several tanks of the series, said branches having controlling valves.

11. In a paper making plant a stock adjusting system consisting of a series of digesting tanks, stock heating means adjacent each tank of the series, means for feeding &

stock consisting of a main feed pipe with valve controlled branches directing stock flowing through each heating means to the several tanks of the series, means for circulating the stock through the heating means and tank of the series consisting of a main circulating pipe with branches communicating with the bottoms of the several tanks of the series and having a series of valve controlling branches directing the flow of the stock through the heating means of the several tanks of the series, and such branches having controlling valves, a pump connected to and forcing the stock through the main circulating pipe, and stock heating means communicating with the said main circulating pipe, and means for discharging the digesting stock from the tank, consisting of a main dischar e pipe with branches communicating with the several tanks of the series, said branches having controlling valves.

12. In the manufacture of paper, the process of preparing the stock for the paper machine consisting in grinding and deckering wood, mixing the deckered ground wood with sulphite pulp, subjecting the mixture intermittently to digesting action and simultaneously heating and stirring the same, and finally cooling and diluting the stock.

13. In the process of manufacturing paper from wood pulp, deflecting the deckered stock and subjecting the same to digestive treatment and then returning it to its sequential order in the paper making process.

In testimony whereof I have signed my name to this specification in the presence of two witnesses.

FRED BARNES.

Witnesses:

HERMAN S. RYLAND, Jos. L. SAssEUR. 

